I have a Mac Pro with Six (6) 3.3 GHz Cores, solid state hard drive, etc.

When I have a single instrument (Antidote) loaded and cycle through patches while playing I get the "Computer is too slow" message and am forced to restart Reason. No other instruments cause this issue.

It's gotten so I've just uninstalled Antidote so I don't accidentally load it up and break my flow.